Dresden 2006 – wissenschaftliches Programm
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MA: Magnetismus
MA 20: Poster: Films(1-36) Transp(37-56) Ex.Bias(57-67) Spindyn(68-80) Micromag(81-95) Particle(96-109) Imag.+Surface(110-113) Spinelectr(114-122) Theory+Micromag(123-131) Spinstr+Aniso(132-142) MagMat(143-156) Meas(157,158) MolMag+Kondo(159-162) Postdead(163-)
MA 20.165: Poster
Dienstag, 28. März 2006, 15:15–19:15, P1
Determination of the directions of the induced moments at Cd probes on Ni surface sites — •P. M. Imielski1, Y. Manzhur2, J. Schubert2, W. D. Brewer1, W.-D. Zeitz2, and M. J. Prandolini2 — 1Institut für Experimentalphysik (WE1), Freie Universität Berlin, 14195 Berlin, Germany — 2Bereich Strukturforschung, Hahn-Meitner-Institut Berlin GmbH, 14109 Berlin, Germany
In recent experiments the magnitude of the magnetic hyperfine fields (∣Bhf∣) of nonmagnetic Cd probe atoms, positioned at different sites onto Ni(111) and Ni(001) surfaces, were measured with atomic resolution, using perturbed angular correlation (PAC) spectroscopy [1]. These surface sites can be characterised by differing coordination numbers, (i.e., the number of Ni nearest neighbours (NN)) [1]. The initial proposition for the direction of the induced Cd moments with respect to the magnetisation of Ni at the coordination number 5 (the free step site) was found to be in conflict with density-functional theory (DFT) calculations [2]. These initial DFT calculations were performed without lattice relaxation. Later DFT estimates, with lattice relaxation, determined the opposite sign at this position [3]. In order to compare the experimental results with theory, we have measured the signs of the Bhf at coordination numbers NN= 9, 7, 5 and 4.
[1] K. Potzger, A. Weber, H. H. Bertschat, W.-D. Zeitz, and M. Dietrich, Phys. Rev. Lett. 88, 247201 (2002).
[2] Ph. Mavropoulos, J. Phys.: Condsened Matter 15, 8115 (2003).
[3] V. Bellini, S. Cottenier, M. Cakmak and F. Manghi and M. Rots, Phys. Rev. B 70, 155419 (2004).